Re: [RFC PATCH] powerpc/fsl: Add barrier_nospec implementation for NXP PowerPC Book E
From: Diana Madalina Craciun <hidden>
Date: 2018-06-01 14:58:14
On 6/1/2018 1:40 PM, Michael Ellerman wrote:=0A=
Scott Wood [off-list ref] writes:=0A= =0A=quoted
On Thu, 2018-05-31 at 14:35 +0000, Diana Madalina Craciun wrote:=0A=quoted
On 5/31/2018 5:21 PM, Michael Ellerman wrote:=0A=quoted
We can add a nospectre_v1 command line option if necessary.=0A=What about nobarrier_nospec (or similar) instead of nospectre_v1 comman=
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line? We are not disabling all the v1 mitigations, the masking part wil=
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remain unchanged.=0A=I think nospectre_v1 makes more sense as it's about the user's intention=
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rather than the implementation. The user is giving the kernel permissio=
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not defend against spectre v1, and it's up to the implementation which=
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mitigations (if any) to disable in response to that, same as any other=
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optimization.=0A=Yeah I agree. We also have `nospectre_v2` on x86/s390 so I think keeping=
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consistency with that is a must.=0A= =0A= cheers=0A= =0A=
OK=0A= =0A= Diana=0A= =0A=